Help me figure out my rough idle and stalling

[Avetiso]

Thought I'd have this taken care of by now, but the problem still pesters me.

Issue: rough idle, often jumps up to 900, or falls to 500 and starts vibrating. Car often stalls out, but it's not a rough stall. Just dies.

Items that have been replaced:

DISA rebuilt
VANOS rebuilt
New NGK plugs
New fuel filter
New VCG
ICV cleaned
Intake boots inspected (still good from what I remember, but having issues raises doubts)
Intake filter is new and freshly oiled
Oil is also new
Shell 91 gas only

No check engine codes.

73.5k miles. My assumption is fuel pump, but I have no issues with high-end fuel delivery at all, and my revs are always responsive. When I press the pedal, I always get power.

Possibly related: I hear a whistling noise when I'm not heavy on the gas. Pretty sure it's my intake, but I haven't noticed it until now. Might be a vacuum leak somewhere? Haven't checked my CCV hoses. No issues with oil consumption.

Up to this point, I've just thrown money at it because it was good maintenance, regardless. But now, I'm not sure what it is.

[kayger12]

Time for a smoke test. Sounds like a vacuum leak somewhere. Especially given the whistle.

[Avetiso]

Time for a smoke test. Sounds like a vacuum leak somewhere. Especially given the whistle.

Any common places (hoses, seals, caps) that are common culprits? Might try replacing some old hoses before I get a smoke test, and it's good maintenance.

[kayger12]

I'd start with the intake boot since you said you have some concerns there. The F connector on the intake boot would be another spot.

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[Vas]

I would replace the intake boots IMO.

[kayger12]

Tough, though, since you're not getting any codes.

Intake plenum gaskets as well since you're hearing that intake whistle.

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[Avetiso]

I guess I'll order new boots when money comes around. I have my cousin coming over soon; I'll have him give some revs while I poke around in the engine bay.

Really hope I don't have to take my manifold off.

[Mtnman]

The most common thing with those symptoms would be intake boots. Upper or lower. They are cheap. Should be less than $50 for the pair. Lower intake boot sucks to replace, just because of its location, but beside that it is a super easy DIY. At the age of the car (age, not mileage) i would think they would be suspect.

[Avetiso]

The most common thing with those symptoms would be intake boots. Upper or lower. They are cheap. Should be less than $50 for the pair. Lower intake boot sucks to replace, just because of its location, but beside that it is a super easy DIY. At the age of the car (age, not mileage) i would think they would be suspect.

Yeah, well that's the thing. When I was in there, I checked them out, and they looked fine. I'm just doubting whether I saw correctly, or maybe missed a crack somewhere. I guess I'll replaced it regardless, but I'm not convinced that's the issue.

[Vas]

Weird that there are no codes being thrown. How is your maf sensor ? Try cleaning it ?

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